1. Field of the Invention
The present invention relates to a network device, and in particular to a network device in which setting a configuration definition is remotely performed.
Together with a recent highly developed communication technology, a network device configuring a network has been provided with various functions supporting a VLAN network or the like, and has become more and more complicated and sophisticated. In many cases, a setting operation for making the network device support a predetermined VLAN network, namely a setting operation of a configuration definition is remotely performed from a terminal. In such a setting operation, it is important to hold a connection of a setting operation path between the network device and the terminal.
2. Description of the Related Art
As an example of a prior art network device, a router can be mentioned for connecting a LAN structured in a small office/home office (SOHO) or the like to an IP network. This router is provided with an operational key and an indicator, and by using these operational key and indicator, sets communication conditions, starts up communication confirmation, makes reference to fault information and the like (see e.g. patent documents 1 and 2).
However, since numerous relevant network devices generally exist, the setting of the network device is not performed on the site of each network device, but is remotely performed from the terminal through a setting operation path. For setting the network device in the IP network, for example, a remote setting operation by using a Telnet connection is general.
For this remote setting operation, a connectivity at an IP level is required between the network device and a setting terminal. In the absence of the connectivity, the network device becomes inaccessible from the setting terminal.
[Patent document 1] Japanese Patent Application Laid-open No. 11-98170 (page 2, FIG. 3)
[Patent document 2] Japanese Patent Application Laid-open No. 11-98171 (page 2, FIG. 3)
A reachability being lost at the IP level between the network device and the terminal during the remote setting operation from the setting terminal is caused by the following error settings (1) and (2):    (1) Error setting of an IP address as a configuration definition (IP address of management VLAN in case of L2 device);    (2) Error setting of a VLAN of a port to which a setting terminal belonging to a management VLAN is connected as a configuration definition (VLAN environment of L2 device).
When the error setting (1) or (2) occurs, the remote setting operation from the terminal is disabled, so that a setting operation by a console connection becomes necessary at a site where the network device is installed.